ARRMA ARAC7778 Pinion Gear 17T ⚙

This steel pinion gear brings dependable engagement for RC drivetrains, offering a compact replacement part that helps maintain smooth power transfer and consistent mesh under load. It suits repairs and upgrades where a durable Mod1 pinion is needed for hobby use, racing prep, or routine maintenance. The opening lines set use and benefit, and the following sections expand on fit, materials and installation notes for a clear buying decision.

Key features

The ARRMA ARAC7778 pinion is crafted in steel for strength and resistance to wear, so it keeps tooth geometry stable after repeated use. ARRMA ARAC7778 appears in a clear fit profile for many Mod1 spur gears, and the 17T count balances acceleration and top speed for common RC setups. Users will notice consistent meshing and reduced risk of stripped teeth when installed with correct backlash, and the modest 5mm bore lets it mount on standard shafts without extra adapters. ⚙️

Tech specs

• Reference: ARAC7778

• Type: Pinion gear

• Material: Steel

• Size: 17T

• Compatibility: Mod1, 5mm bore shafts

Who it’s for

It suits you if you need a long lasting spare or a direct replacement for a Mod1 RC drivetrain that demands tougher components under sustained load. A solid pick if you perform track sessions or hobby bashing and prefer metal gears to prolong service intervals.

It may not suit you if weight or silent operation are primary goals, since steel gears add mass and can transmit more drivetrain noise compared to composite options. Also, double check shaft diameter before buying because this unit is made for a 5mm bore and will not fit smaller shafts without modification. steel construction is mentioned to manage expectations about durability and sound levels.